/*
 *
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <alloca.h>
#include <limits.h>
#include <fm/topo_mod.h>
#include <sys/param.h>
#include <sys/systeminfo.h>
#include <sys/fm/protocol.h>
#include <sys/stat.h>

#include <topo_method.h>
#include <topo_subr.h>
#include <libzfs.h>
#include <zfs.h>
#include <pthread.h>

static int zfs_enum(topo_mod_t *, tnode_t *, const char *, topo_instance_t,
    topo_instance_t, void *, void *);
static void zfs_rele(topo_mod_t *, tnode_t *);
static int zfs_fmri_nvl2str(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);

const topo_method_t zfs_methods[] = {
        { TOPO_METH_NVL2STR, TOPO_METH_NVL2STR_DESC, TOPO_METH_NVL2STR_VERSION,
            TOPO_STABILITY_INTERNAL, zfs_fmri_nvl2str },
        { NULL }
};

static const topo_modops_t zfs_ops =
        { zfs_enum, zfs_rele };
static const topo_modinfo_t zfs_info =
        { ZFS, FM_FMRI_SCHEME_ZFS, ZFS_VERSION, &zfs_ops };

static libzfs_handle_t *g_zfs = NULL;
static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
static int g_refcount = 0;

int
zfs_init(topo_mod_t *mod, topo_version_t version)
{
        /*
         * Turn on module debugging output
         */
        if (getenv("TOPOZFSDEBUG"))
                topo_mod_setdebug(mod);

        topo_mod_dprintf(mod, "initializing zfs builtin\n");

        if (version != ZFS_VERSION)
                return (topo_mod_seterrno(mod, EMOD_VER_NEW));

        if (topo_mod_register(mod, &zfs_info, TOPO_VERSION) != 0) {
                topo_mod_dprintf(mod, "failed to register zfs: "
                    "%s\n", topo_mod_errmsg(mod));
                return (-1); /* mod errno already set */
        }

        (void) pthread_mutex_lock(&g_lock);
        if (g_refcount == 0) {
                if ((g_zfs = libzfs_init()) == NULL) {
                        (void) pthread_mutex_unlock(&g_lock);
                        topo_mod_dprintf(mod, "libzfs_init() failed");
                        topo_mod_unregister(mod);
                        return (topo_mod_seterrno(mod, EMOD_UNKNOWN));
                }
        }
        g_refcount++;
        (void) pthread_mutex_unlock(&g_lock);

        return (0);
}

void
zfs_fini(topo_mod_t *mod)
{
        (void) pthread_mutex_lock(&g_lock);
        g_refcount--;
        if (g_refcount == 0) {
                libzfs_fini(g_zfs);
                g_zfs = NULL;
        }
        (void) pthread_mutex_unlock(&g_lock);
        topo_mod_unregister(mod);
}


/*ARGSUSED*/
int
zfs_enum(topo_mod_t *mod, tnode_t *pnode, const char *name, topo_instance_t min,
    topo_instance_t max, void *notused1, void *notused2)
{
        /*
         * Methods are registered, but there is no enumeration.  Should
         * enumeration be added be sure to cater for global vs non-global
         * zones.
         */
        (void) topo_method_register(mod, pnode, zfs_methods);
        return (0);
}

/*ARGSUSED*/
static void
zfs_rele(topo_mod_t *mp, tnode_t *node)
{
        topo_method_unregister_all(mp, node);
}

typedef struct cbdata {
        uint64_t        cb_guid;
        zpool_handle_t  *cb_pool;
} cbdata_t;

static int
find_pool(zpool_handle_t *zhp, void *data)
{
        cbdata_t *cbp = data;

        if (zpool_get_prop_int(zhp, ZPOOL_PROP_GUID, NULL) == cbp->cb_guid) {
                cbp->cb_pool = zhp;
                return (1);
        }

        zpool_close(zhp);

        return (0);
}

static ssize_t
fmri_nvl2str(nvlist_t *nvl, char *buf, size_t buflen)
{
        uint64_t pool_guid, vdev_guid;
        cbdata_t cb;
        ssize_t len;
        const char *name;
        char guidbuf[64];

        (void) nvlist_lookup_uint64(nvl, FM_FMRI_ZFS_POOL, &pool_guid);

        /*
         * Attempt to convert the pool guid to a name.
         */
        cb.cb_guid = pool_guid;
        cb.cb_pool = NULL;

        if (zpool_iter(g_zfs, find_pool, &cb) == 1) {
                name = zpool_get_name(cb.cb_pool);
        } else {
                (void) snprintf(guidbuf, sizeof (guidbuf), "%llx", pool_guid);
                name = guidbuf;
        }

        if (nvlist_lookup_uint64(nvl, FM_FMRI_ZFS_VDEV, &vdev_guid) == 0)
                len = snprintf(buf, buflen, "%s://pool=%s/vdev=%llx",
                    FM_FMRI_SCHEME_ZFS, name, vdev_guid);
        else
                len = snprintf(buf, buflen, "%s://pool=%s",
                    FM_FMRI_SCHEME_ZFS, name);

        if (cb.cb_pool)
                zpool_close(cb.cb_pool);

        return (len);
}

/*ARGSUSED*/
static int
zfs_fmri_nvl2str(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *nvl, nvlist_t **out)
{
        ssize_t len;
        char *name = NULL;
        nvlist_t *fmristr;

        if (version > TOPO_METH_NVL2STR_VERSION)
                return (topo_mod_seterrno(mod, EMOD_VER_NEW));

        if ((len = fmri_nvl2str(nvl, NULL, 0)) == 0 ||
            (name = topo_mod_alloc(mod, len + 1)) == NULL ||
            fmri_nvl2str(nvl, name, len + 1) == 0) {
                if (name != NULL)
                        topo_mod_free(mod, name, len + 1);
                return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
        }

        if (topo_mod_nvalloc(mod, &fmristr, NV_UNIQUE_NAME) != 0) {
                topo_mod_free(mod, name, len + 1);
                return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
        }
        if (nvlist_add_string(fmristr, "fmri-string", name) != 0) {
                topo_mod_free(mod, name, len + 1);
                nvlist_free(fmristr);
                return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
        }
        topo_mod_free(mod, name, len + 1);
        *out = fmristr;

        return (0);
}